Removable top for soaking pits



W. T. DEAN REMOVABLE TOP FOR SOAKING FITS Original Filed May 17. 1937 mN wn @QN QN a a May 23, 1939.

(lttornc a r U nu u U n 3 Patented May 25, 1939 REMOVABLE TOP FOR SOAKING PITS William '1. Dean, Gary, Ind.

Application May 17, 1937, Serial No.

is a division of application Serial No.

143,226, which 105,336,

October 12, 1936. Divided and this application August 12, 1937, Serial No. 158,820

which the said cover is transferred from open to closed position; and

Figure 3 is a detail sectional view, on an enlarged scale, of one of the intermediate suspending skews employed in the cover organization shown in Figure 1.

Referring to Figure l which shows a partial sectional elevation of a soaking pit with an improved cover 28, to Figure 2 which shows a partial plan view of same, and to Figure 3 which shows a section through one of the intermediate skew backs 28b and alloy supports for said cover, the cover comprises a series of short arches 28a 11 Claims.

This tipplication is a division of my application Serial No. 143,226, filed May 17, 1937, for Removable tops for soaking pits, which in turn is a division of my application Serial No. 105,336, filed 6 October 12, 1936, for Soaking pits and like heating furnaces, and the invention relates specificaliy to covers or doors for said pits.

Retractable covers or doors as heretofore built leave much to be desired in point of life and insulation. Where such covers are supported by a truck carried on rails along the side of the pit, sufficient space for overlap is lacking; the view of the pit by the craneman is limited; and high cover and pit top repairs follow. Where the covers are carried on trucks, it is impossible to secure good sealing because, if the cover be lowered to seat well, the weight is of! the axles and no traction remains. Unless covers are well sealed, they permit serious heat losses as well as infiltration at times and damage to the cover edge castings and channeling of pit tops. For small pits, covers may be made with a cast steel frame lined with a spherically shaped arch of fire brick. For large pits, however, it is necessary to use structural cover frames, for which spherical arches are not suitable because of the diiliculty of providing for the arch thrusts and because of the volume of space formed beneath such arches. This has forced the use of flat or suspended arches of refractory units, supported by special hanger castings that rest upon the structural frame members. This ime of cover is expensive in first cost and short lived because there is no means of keeping the brick elements tight, and further insulation cannot be applied as the hanger castings become overheated. The racking of such covers due to movements accentuate the difllculties.

One object of the present invention is to provide a multiple arched cover which will afford ready access to furnaces and the like for inspection and cleaning and which may be insulated; also a cover that will remain tight in spite of movements, reduce the number of special brick shapes required, and eliminate hanger castings susceptible to damage by heat.

Other objects are to provide means for lowering and sealing covers on pit tops; to avoid the use of retracting mechanism in hot zones; and to eliminate hydraulic cover operating mechanism.

In the accompanying drawing Figures 1 and 2 are, respectively, a vertical longitudinal section of a portion of the pit, and a top plan view of the same together with its portable cover and the carriage through means of across the short dimension of the cover.

The

end skew backs 28c are supported by the end frames 23d at each end and by suspended alloy bars Me at intermediate points. The arch thrust is taken by the side frames of the cover supplemented by a heavy central arch tie rod 28!. The skews are made from first quality fire brick and are the only special shapes required. The arch brick 28a may be standard 9" brick or may be 2500 degree insulating brick, requiring no extraneous insulation and greatly reducing the total weight of a cover.

If standard fire brick arches be used, additional insulation may be added without fear of destroying the supporting hangers. As shown in Figure 3, skews 281) are made in two mated parts that embrace the alloy hanger bar 28c, while copper radiator bar 28a is welded to the alloy hanger bar between the supporting alloy bolts 2th and projects above the brick skews for exposure to atmosphere in giving off its heat and preventing overheating of the alloy bar which is entirely surrounded by brick. In practice, the alloy bar is rolled from chromium-nicked (18/8) one and one-half by two inches and the radiator bar is one-quarter inch b six inches.

The cover frame comprises structural channels and beams ill with bar cross bracing 28k (Figure 2), all securely welded. A series of simple steel or alloy castings 28L along the ends, bolted to the frame members, support the end skews 28c, while similar castings along the sides support standard fire brick blocks 28m and close the ends of the cross arches.

The completed cover is supported pivotally on its transverse center line from a pair of cantilevers 28 extending from a truck 30 placed at one end of the pit, as shown. The truck is provided with four wheels 30a, 30b, keyed to axles 30c and partially counterweighted and actuated by a motor drive comprising a motor 3|, reducer lid and chain drive 31b to one rear axle Illc.

When the cover is in place as shown, its

weight rests upon the pit top. When moved, the cover is raised by means of a section 32:: of internal geared inverted rack 32 engaging gears 306! on the driving axle; said gears and rack having the same pitch diameter. The cover rises with a slight rolling action and descends similarly, thus aiding a good seal on the flat top of the pit. A corresponding motion in the opposite direction for pit inspection may be had by completing the rack curve in the opposite direction, in conjunction with a short section 32b of straight track. When suspended, the weight of the cover rests upon the front axles, the rear axles being held down by the inverted rack 32 and straight section 321) adjoining same. The entire track system is securely attached to the pit steel work. It will be noted that all retracting mechanism is located away from the pit so that neither motor, leads nor drive can be subjected to heat hazard. Inspection ports 33 may be cut through the first arch at desired points for inspection, at angles suitable for the purpose, so that frequency of cover movements for inspection is greatly reduced. It will be noted that the arch rise is slight, avoiding large dead cavities above the pit top. Further, the series of small arches 28a and skews 28b has proven beneficial in practice, causing the flames to undulate, increasing turbulence within the pit with increased convection heating. It has been found that insulating brick arches have long life, that the covers remain tight as vibration due to motion tends to tighten the arches, and that heat lost through covers has been reduced to a negligible amount, the actual time of heating being reduced materially. The intermediate skews are elevated slightly above the end skews, thus avoiding any possible drag on the pit top. It will be noted that while it is possible to operate a cover as described by means of hydraulic rams as has been common practice in the art heretofore, such an operating mechanism is no longer necessary with its attendant danger of freezing and water leaks. The controlling mechanism for covers and heating may be located on a light structural bridge spanning the cover retracting mechanism, giving heaters an unobstructed view of the pits and covers. It will be noted that when the covers are retracted. the pit top is free of all obstructions so that crane operators have full view into the pit for charging and drawing steel with lessened danger of damage to pit walls and top, also that the pits are fully accessible for brick repairs when needed. It will be noted further that the removal of supporting rails or track along the sides of the pit tbps permits suitable overlap for the covers, previously limited by such rails, thereby increasing the life of covers and pit tops.

What is claimed is:

1. A cover for heating furnaces, comprising a series of short sprung arches of insulating fire brick, end and intermediate supporting skews for said fire brick, heat resisting bars for supporting said skews, heat radiating fins extending from said bars, and means for supporting said skews independently of said fins.

2. A cover for heating furnaces, comprising a series of short sprung arches of refractory material, intermediate and end skews supporting said arches, a cover frame supporting the end skews, cross bracing supported by said cover frame and disposed adjacent said intermediate skews, and means carried by said cross bracing for supporting said intermediate skews.

3. A cover for heating furnaces, comprising a series of short sprung arches of refractory material, intermediate and end skews supporting said arches, a cover frame supporting the end skews, cross bracing supported by said cover frame and disposed adjacent said intermediate skews, an arch tie rod secured to and extending between the end members of said cover frame, and means carried by said cross bracing for supporting said intermediate skews.

4. A cover for heating furnaces, comprising a. series of short sprung arches of refractory material, intermediate and end skews supporting said arches, a cover frame supporting the end skews, cross bracing supported by said cover frame and disposed adjacent said intermediate skews, heat resisting bars associated with said intermediate skews, and means connected to said cross bracing and said bars for supporting said intermediate skews.

5. A cover for heating furnaces, comprising a series of short sprung arches of refractory ma-. terial, intermediate and end skews supporting said arches, a cover frame supporting the endskews, cross bracing supported by said coverframe and disposed adjacent said intermediate skews. heat resisting bars embraced by said intermediate skews, and means connected to said cross bracing and said bars for supporting said intermediate skews.

6. A cover for heating furnaces, comprising a series of short sprung arches of refractory material, intermediate and end skews supporting said arches, a cover frame supporting the end skews, cross bracing supported by said cover frame and disposed adjacent said intermediate skews, heat resisting bars associated with said intermediate skews, heat radiating fins extending from said bars, and means connected to said cross bracing and said bars for supporting said intermediate skews.

7. A cover for heating furnaces, comprising a series of short sprung arches of refractory material, intermediate and end skews supporting said arches. a cover frame supporting the end skews, cross bracing supported by said cover frame and disposed adjacent said intermediate skews, heat resisting bars embraced by said intermediate skews, heat radiating fins extending from said bars, and means connected to said cross bracing and said bars and independent of said fins for supporting said intermediate skews.

8. A cover for heating furnaces, comprising a series of short sprung arches of refractory material, intermediate and end skews supporting said arches, a cover frame supporting the end skews, cross bracing supported by said cover frame and disposed adjacent said intermediate skews, an arch tie rod secured to and extending between the end members of said cover frame, heat resisting bars embraced by said intermediate skews, heat radiating fins extending from said bars, and means connected to said cross bracing and said bars and independent of said fins for supporting said intermediate skews.

9. A cover for heating furnaces, comprising a series of short sprung arches of refractory material, intermediate and end skews supporting said arches, a cover frame supporting the end skews, cross bracing supported by frame and disposed adjacent said intermediate skews, heat resisting bars associated with said intermediate skews, and means carried by said cross bracing for supporting said intermediate skews.

said cover areas 3 ried by said cross bracing for supporting said intermediate skews.

11. A cover for heating furnaces. comprising a series of short sprung arches of insulating fire brick, end and intermediate supporting skews for said fire brick, and means for supporting said end and intermediate skews.

wns-nm '1'. pm.

CERTIFICATE OF CORRECTION.

Patent No 2, 159,814.14.-

WILLIAM T DEAN.

It is hereby certifiedthat error appears in the printed specification ofthe above numbered patent requiring correction as follows:

"chromium-nicked" read chrome-nickel; line 58, he said Letters Patent should be read 0nd column, line 56, for for "b six" read by six; and that t with this correction therein that the same may conform the case in the Patent Office.

Page 1, secto the record of Signed and sealed this Lith. day of July, A. D. 1959.

Henry Van Arsdale Acting Commissioner of Patents.

areas 3 ried by said cross bracing for supporting said intermediate skews.

11. A cover for heating furnaces. comprising a series of short sprung arches of insulating fire brick, end and intermediate supporting skews for said fire brick, and means for supporting said end and intermediate skews.

wns-nm '1'. pm.

CERTIFICATE OF CORRECTION.

Patent No 2, 159,814.14.-

WILLIAM T DEAN.

It is hereby certifiedthat error appears in the printed specification ofthe above numbered patent requiring correction as follows:

"chromium-nicked" read chrome-nickel; line 58, he said Letters Patent should be read 0nd column, line 56, for for "b six" read by six; and that t with this correction therein that the same may conform the case in the Patent Office.

Page 1, secto the record of Signed and sealed this Lith. day of July, A. D. 1959.

Henry Van Arsdale Acting Commissioner of Patents. 

